Portable breath analyzer sensors will detect molecules from a range of hydrocarbons without distinguishing - so don't gargle JP4.
Athletes, diabetics and weight-losers may have a lot of Ketones in their breath, which can make a dramatically high false reading.
Blood tests are more accurate, but lab people are not always up to par. If you ever are in a situation where you must involuntarily give a sample, politely demand that they run two blood samples, taken at the same time, in two different labs. Might save your bacon if you are not up to serious mischief.
BA is metabolically really a measure of the ratio of alcohol to water in the body. If you are dehydrated, that increases chances of a bad test (as well as a mal di testa). To rescue onesself from an error of judgement, drink water - and pass it - like a pump. Heavy breathing - lots of it - can lose quite a bit through the lungs.
(This info is 8-9 tenths reliable. Learned it as an investor in a BA instruments company a few years back.)
In vino veritas - unfortunately. Fly safe.